Exhaust gas muffler means

ABSTRACT

An exhaust gas muffler means adapted to be provided in a gas exhaust pipe of the internal combustion engine and the like, comprising a series of buffing elements arranged in and along the gas exhaust pipe. Each buffing element comprises a blind chamber, a throat and a plurality of outlets. The buffing elements are communicated with one after another intermediate a part of the gas exhaust pipe or directly. Not only the barking sounds but also low frequency noise are damped and deadened.

United States Patent Inventors Hiroshi lhsui;

Eizo Suylrna, both of Tokyo, Japan 782,607

Dec. 10, 1968 June 29, 197 1 Nikon Radiator Co., Ltd.

Tokyo, Japan Appl. No. Filed Patented Assignee izxiuus'r GAS MUFFLERMEANS 17 Claims, 22 Drawing Figs US. Cl 181/36, 181/54,181/59 Int. ClF011: 1/02, FQln 1/Q8, F01n 7/08 Fieldoisearch 18l/53,54, 36, 36.2, 48,59

[56] References Cited UNITED STATES PATENTS 1,084,290 1/1914 Pelletier181/53 X 2,576,522 11/1951 Kyfi'm 181/59 X FOREIGN PATENTS 33,93211/1964 Germany 181/53 839,063 12/1938 France 181/54 PrimaryExaminer-Robert S. Ward, Jr. Att0rneySteinberg and Blake ABSTRACT: Anexhaust gas mufiler means adapted to be provided in a gas exhaust pipeof the internal combustion engine and the like, comprising a series ofbuffing elements arranged in and along the gas exhaust pipe. Eachbuffing element comprises a blind chamber, a throat and a plurality ofoutlets. The buffing elements are communicated with one after anotherintennediate a part of the gas exhaust pipe or directly. Not only thebarking sounds but also low frequency noise are'damped and deadened.

PATENTEI] me m V 3.589 A69 SHEET 2 [1F 3 INVENTORS, H/ROSH/ 11 /13 0/ f12/20 1/ YA MA ZICLWL g 1/ W PATENTEU JUN29 19?:

SHEET 3 UF 3 F g- 2 l LL L-L-L I NVENTORS S #0 Y B v'l aig EXHAUST GASMUFFLER MEANS BACKGROUND OF THE INVENTION 1. Field of the Invention Thefield of art to which this invention pertains is a device through whichthe exhaust gases from an internal combustion engine and the like arepassed to suppress the audible vibrations.

2. Description of the Prior Art The exhaust sound generated by theexhaust of the internal combustion engine and the like is roughlydivided into two classes. The first one is the pressure waves of ratherlow frequency accompanied by the exhaust gas burnt in and exhausted fromthe cylinders of the engine. The other is the acoustic waves of ratherhigh frequency generated by the expansion of the exhausted gas, as shownin FIG. 2 The pressure waves A are of range of from 30 to 200 cycles persecond depending upon the rotation of the engine and characterized bythe small negative pressure. The acoustic waves B are mixed waves of arange of from 100 to 5000 cycles per second of which the positivepressure and the negative pressure are evenly distributed. The pressurewaves A are more than times of the acoustic waves in energy level. Incase of the ex haust sound of the internal combustion engine, energy ofthe pressure waves is substantially larger than that of the acousticwaves which is extremely small.

I-Ieretofore, a muffler is such that a cavity having a larger diameterthan an exhaust pipe is formed in a suitable location in the pipe anddivided into several chambers having suitable volumes by baffle plates.These chambers are communicated with one after another on the basis ofthe acoustic theory of plane waves so as to function as an expandingchamber, a resonant chamber, an interfering chamber, and an absorbingchamber (which may be filled with a sound absorbing material) and thusintended to damp out sounds mainly of high frequency. Such noise asaccompanying pulsative dynamic pressure of pressure waves andintermittent flow of gases, of which energy is 10 times of that of soundwaves, as produced by the piston type internal combustion engine, thecompressor, and the like is subsidiarily depressed and rectified byimpedance among the above-mentioned expanding chamber, resonant chamber,interfering chamber and absorbing chamber as far as the prior artconcerns. In addition, it has been difficult to deaden sounds of lowfrequencies caused by the pulsative dynamic pressure of pressure wavesand intermittent flow of gases, by the conventional muffler due to arestriction in the setting position and the size thereof, particularlyin an automobile.

One object of this invention is to provide an exhaust gas muffler means,in which the pulsative dynamic pressure of intermittent flow of gasesaccompanying such pressure waves as causing the low frequency sounds isintroduced into a buffing chamber, in which the pressure is buffed andabsorbed by adiabatic compression by virtue of elasticity of the gases,so as to reduce low frequency sounds generated secondarily at thetailpipes.

Another object of this invention is to provide an exhaust gas mufflermeans, which may be mass-produced from an inexpensive metal pipe andhave alight and strong structure and in which the weight islongitudinally evenly distributed.

Still another object of this invention is to provide an exhaust gasmuffler means, in which it is possible to damp low frequency acousticwaves and pressure waves by virtue of an exhaust pipe of which thelength is several times substantially while appearing compact, so thatthe same is suitable to fit an exhausting system having a relativelyshort exhaust pipe.

A still further object of this invention is to provide an exhaust gasmuffler means, which may be useful independently or in combination withthe conventional muffler.

A still further object of this invention is to provide an exhaust gasmuffler means, which may be easily standardized by virtue of a minimizednumber of parts thereof, so that another SUMMARY OF THE INVENTION Inaccordance with they general feature of this invention,

there is an exhaust gas muffler means adapted to be provided in a gasexhaust pipe of the internal combustion engine and the like, comprisinga series of buffing elements arranged in and along the gas exhaust pipe.Each of the buffing elements comprises a blind buffing chamber having atleast a throat and a plurality of outlets. The exhaust gas is introducedinto the buffing chamber through the throat and expelled out of thebuffing chamber through the outlets communicated with the throat of thesubsequently arranged buffing element exclusive of the foremost throatand the hindmost outlets. And the outlets are positioned so as to directthe exhaust gas sidewise in connection with the direction of theincoming exhaust gas.

The efficiency in the buffing chamber depends mainly upon the volumethereof and the total sum of the areas of the outlets. In general, thelarger the volume of the buffing chamber, the larger the buffing actionagainst the pressure waves becomes, and the negative effect of a largetotal area of the outlets is reduced by thus enlarged volume. However,if it is intended to enlarge the effect for damping action by means ofreduced total area of the outlets, the resistance to the exhaust gasflow is increased. Under these circumstances, it is necessary to selectsuitable values for these variations in view of still furtherconditions.

A plain pipe having a length of the conventional muffler used for aconventional automobile was connected with an engine for measuring thepressure distribution of the exhaust gas of the engine, resulting in tofind that the pressure distribution became a constant state by a usualoperation of the engine and that only several nodes and loops existedalong the pipe. Therefore, it is possible to amplify the effect of thebuffing element by mounting the same at the node, where the pressure ofthe pressure waves is peaked, upon detection of such nodes. However, itis not preferred to increase the number of the buffing elements beyondan extent, because the resistance to the exhaust gas flow is increasedas the number increases.

In order to design the buffing element, of which elastic coefficient hasbeen adjusted so as to effectively damp and absorb the energy of thepulsative dynamic pressure of the pressure waves and intermittentexhaust gas flow, it is preferred to satisfy the following formula:

wherein f represents t e resonance oscillation frequency of the buffingchamber, 3 represents the acceleration of gravity or 980 cm./sec. Wrepresents the absolute pressure subjected to the buffing chamber fromthe throat by the pressure waves and the intermittent flow of theexhaust gas (in unit of kg./cm. and K represents the elastic coefficientof the buffing chamber, of K=AkP,,S/H,, in which A is the proportionalconstant, k is the polytropic index, P is the pressure inside thebuffing chamber, S is the cross-sectional area of the throat, and H isthe lateral length of the buffing chamber.

BRIEF DESCRIPTION OF THE DRAWING The invention will be better understoodand other objects and additional advantages of the invention will becomeapparent upon perusal of the following description taken in connectionwith the drawings, in which:

FIG. 1 is a plan view of an example of a conventional muffler for theautomobile;

FIG. 2 is a graph indicating a property of an exhaust sound of aninternal combustion engine;

FIG. 3 is a plan view of an embodiment of the exhaust gas muffler meansin accordance with this invention;

FIG. 4 is a plan view of another embodiment of the exhaust gas mufflermeans in accordance with this invention;

FIG. 5 is a perspective view of a buffing element provided in theembodiment shown in FIG. 3, showing the structure of the buffingelement;

FIGS. 6 and 7 are perspective views showingmoditication's of the buffingelement shown in FIG. 3, respectively;

FIGS. 8, 9, 10 and 11 are axially sectional views of further embodimentsof the buffing element shown in FIG. 4, respectively;

FIG. 12 is a perspective view of a guide shown in FIG. 11;

FIGS. l3, 14, 15 and 16 are axially sectional views of still furtherembodiments of the buffing element shown in FIG. 4,

respectively;

FIGS. 17, 19 and 21 are axially sectional views of still furtherembodiments of the bufiing elements which constitute appreciable lengthsof the gas exhaust pipe in accordance with this invention, respectively;and

FIGS. 18, and 22 are cross-sectional views of the buffing elements shownin FIGS. 17, 19 and 21, respectively.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Referring more particularly tothe drawings, the preferred embodiments of this invention will now bedescribed; however, this description will be understood to beillustrative of the invention and not as limiting it to the particularconstructions shown and described. An exhaust pipe is provided with aplurality of buffing elementsQAn exhaust pipe 20 is provided isprotruded outside the exhaust pipe 22 so that it is possible to make thepipe 22 thin, but the buffing element 23 is rather big. In view of thesefacts, it is preferred that either of the above two types is selected orthey are suitably combined with each other considering, for example,ground clearance of an automobile.

In FIGS. 5 to 7, inclusive three embodiments of the buffing element 21are illustrated. A buffing element 21 shown in FIG. 5 comprises threeparts: a big pipe 24 and a thin pipe 25 are connected with each otherintermediate a frustoconical pipe 26. The big pipe 24 is fit and joinedinside the exhaust pipe 20. The head end 27 is opened. The tail end 28is closed. A plurality of perforations 29 are perforated through thehead part of the thin pipe 25. The interior of the thin pipe 25 betweenthe perforations 29 and the closed tail and 28 functions as a buttingchamber.

A buffing element 21 shown in FIG. 6 comprises also three parts: a bigpipe 30 and a thin pipe 31 are connected with each other intermediate afrustoconical pipe32. The big pipe 30 is fit and joined inside theexhaust pipe 20. The tail end 34 of the big pipe 30 is opened. The headend 33 oi the thin pipe 31 is closed. A plurality of perforations 35 areperforated through the head part of the tubular wall of the thin pipe3!. A longitudinally tubular space between the wall of the exhaust pipe20 and the wall of the thin pipe 31 extending from the perforations 35to the frustoconical pipe 32 functions as a buffing chamber.

A butting element Mshown in FIG. 7 is appreciably different fromtheabove two embodiments, which comprises a length of pipe 36 fit andjoined inside the exhaust pipe 20. The

wall of the inside pipe 36 is formed with some longitudinal in tcrnallyfluted parts 37 so as to form longitudinal troughs inside the wall ofthe exhaust pipe 20. Therefore, if the number of such troughs 37 isfour, the cross section of the inside pipe 36 is cruciform. The head end38 of the inside pipe 36 is opened and the tail end 39 thereof isclosed. The troughs 37 are open at both ends. The interior of the insidepipe 36 functions as a buffing chamber. I

In FIG. 8 an embodiment of the buffing element 23 shown in FIG. 4 isillustrated. The buffing element 23 shown in FIG. 8 comprises a part ofthe exhaust pipe 22 pinched into closure 40. The wall of the exhaustpipe 22 is circumferentially partly cut into two parts: a front part 41and a rear part 42. The tail end of the front part 41 is closed as aboveThe head end'43 of the rear pipe 42 is opened externally. The front pipe41 is formed with a'plurality of perforations 44 lying somewhere shortof the closure 40. An outer tubular casing 45 is jointed with the tailpart of the front pipe 41 and the head part of the rear pipe 42 so as tocover the perforations 44 and some length of the head part of the rearpipe 42. Two blind spaces, one 46 in the front pipe 41 and the other 47outside the rear pipe 42, serve as buffing chambers.

In FIG. 9 another embodiment of the buffing element 23 shown in FIG. 4is illustrated. This buffing element 23 is located at the rear end of afront exhaust pipe 48. The'head end 49 of a big pipe 50 is jointed withthe big end of a reducer 51, of which the thin end 52 is jointed withthe tail end of the front exhaust pipe 48. A rear exhaust pipe 53 havingthe same diameter with the front exhaust pipe 48 is inserted into thetail end 54 of the big pipe 50. The tail end 54 is jointed with the rearexhaust pipe 53 by means of another reducer 55. The head end 56 of therear exhaust pipe 53.is extended to the head end 49 of the big pipe 50and somewhat reduced. The head end 56 is surrounded at a distance by agas guide 57 of a semispherical wall which is supported in place by asuitable means inside the reducer 51.

In operation of this embodiment, the exhaust gas departing from thefront exhaust pipe 48 is guided by the guide 57 into the tubular blindspace 58 formed between the big pipe 50 and the rear exhaust pipe 53,whence the same is introduced into the rear exhaust-pipe 53 through theannular space between the guide 57 and the head end 56 of the rearexhaust pipe 53. The tubular blind space 58 functions as a buffingchamber.

The exhaust gas once compressed in the buffing chamber 58 is reactivelyexpanded, borne by the guide 57, and deflected into the head end 56 ofthe rear exhaustpipe 53. The head end 56 is reduced from a diameter to aless diameter whereby the resistance subjected to the exhaust gas streamis reduced.

The buffing element 23 shown in FIG. 9 may be bent in whole to an extentas shown in FIG. 10, so as to facilitate its arrangement in a case.

A buffing element 23 shown in FIG. 11 is somewhat similar to that shownin FIG. 9. The buffing element comprises a big pipe 60 of which bothends are reduced, the head end 61 being adapted to be closely insertedinto the tail end 62 of the front exhaust pipe 63 and the tail end 64 ofthe big pipe 60 being adapted to be closely inserted into the head end65 of the rear exhaust pipe 66. Another pipe 67, of which the tail end68 is closely inserted into the tail end 64 of the big pipe 60, isextended inside the big pipe 60 ahead to a guide 69.. The guide 69comprises a semispheroidal wall having three axial ribs 70 which areadapted to fit closely in the big pipe 60 so as to form three trisectedannular passages 74', as shown in FIG. 12. The head end 71 of the insideanother pipe 67 is engaged with and in the guide 69 and fixed thereby inplace. Several axial slots 72 are formed in the head end 71 of theinside another pipe 67.

In operation of this embodiment, the exhaust gas departing from thefront exhaust pipe 63 is guided by the guide 65 through the threetrisected annular passages 74 into a tubular blind space 73 formedbetween the rear part of the big pipe 69 and the inside another pipe 67,whence the gas is admitted inside the inner another pipe 67 communicatedwith the rear exhaust pipe 66, through the interiors of the three ribs70 and the slots 72 of the inner another pipe 67.

A buffing element 23 embodying this invention as shown in FIG. 13comprises the tail end of the front exhaust pipe 75. The tail end isexpanded into a buffing chamber '76 and surrounded at a distance fromand by a big pipe 77 together with a throat 78 positioned in front ofthe buffing chamber 76 and several perforations 79 formed in the wall ofthe front exhaust pipe 75. The exhaust gas gone right on in the frontexhaust pipe is once compressed in the buffing chamber 76, whenceadmitted into the big pipe 77 through the perforations 79. Of course,the big pipe 77 serves as a supporting member for the whole structure.

Another buffing element 23 shown in FIG. 14 differs from the precedingembodiment in that the tail end 80 of. the front exhaust pipe 88 isopened inside a buffing chamber 81 formed by a big pipe 82, a frontpartition 83 and a rear partition 84, and that a rear exhaust pipe 85 isextended through the buffing chamber 81 into a front chamber 86 in frontof the buffing chamber 81 and terminated with an open head end 87. Theperforations 89 and the throat 90 are formed and positioned similarly tothe preceding embodiment.

Still another buffing element 23 shown in FIG. is quite similar to thepreceding embodiment in accordance with this invention except that thetail end 91 of the front exhaust pipe 92 is closed so that theinterior'of the closed end 91 constitutes a buffing chamber 92 byitself.

The preceding embodiments of the buffing elements 21 and 23 inaccordance with this invention are all cylindrical in shape, but it isnot necessary to shape so. FIG. 16 illustrates a buffing element 100,which is spheroidal in shape. The tail end 101 of the front exhaust pipe102 is opened and protruded inside a spheroidal chamber 103 which is ablind buffing chamber. A larger spheroidal casing 104 surrounds at adistance the smaller spheroidal chamber 103 and is communicated with thefront exhaust pipe 102 by several perforations 105 formed in the wall ofthe front exhaust pipe 102 between the head end of the larger spheroidalcasing 104 and the smaller spheroidal chamber 103. The larger spheroidalcasing 104 is extended into a rear exhaust pipe 106 from the tail end ofthe casing 104. The tail end 101 of the front exhaust pipe 102 is thethroat of the buffing chamber 103.

Now there are further three embodiments of this invention which areappreciably different from the preceding embodiments in appearance, asshown in FIGS. 17 to 22, inclusive. However, these embodiments belong tothe series of the buffing elements 21 shown in FIGS. 3, S, 6 and 7. Inthe embodiments shown in FIGS. 3, 5, 6 and 7, the buffing chamber isarranged concentrically to the exhaust pipe, while in the embodimentsshown in FIGS. 17 to 22, the buffing chamber is arranged eccentricallyto and inside the exhaust pipe. The buffing chambers in the formerembodiments are intermittently arranged in and along an exhaust pipe,while those in the latter embodiments are continuously arranged in andalong an exhaust pipe.

In an embodiment shown in FIGS. 17 and 18, there is an exhaust pipe 110which is longitudinally bisected by a longitudinal partition 111 so asto form two longitudinal compartments having semicircular crosssections, respectively. These longitudinal compartments are divided intounit compartments similarly with each other by radial partitions 112.However, these radial partitions 112 of the two longitudinalcompartments are zigzag arranged so that the unit compartments are alsozigzag arranged. There are several, for example, four perforations 113formed in the longitudinal partition 111 in the proximity of the headend of each unit compartment so as to communicate one of the one sideunit compartments with one of the other side unit compartments. Becausethese unit compartments are zigzag arranged, all unit compartments arecommunicated successively one after another. The location of theperforation 113 in a unit compartment is the proximity of the head endthereof and a part somewhat rearwards from the longitudinal center,which corresponds to the head end of the next unit compartment belongingto the other side, so that there is formed a blind chamber 114 betweenthe said part and the tail end of the unit compartment. This individualblind chamber 114 functions as a buff ng chamber. These zigzag arrangedbuffing chambers 114 may be continuously arranged longitudinally in theexhaust pipe 110 as long as desired.

FIGS. 19 and illustrate an exhaust pipe 120 formed with a series of unitcompartments defined by radial partitions 121 similarly to the precedingembodiment. However, this exhaust pipe 120 is longitudinally trisectedby the longitudinal partitions 122 and the radial partitions 121 arearranged in such a manner that between any adjoining two belonging to alongitudinal compartment are positioned one radial partition of anotherlongitudinal compartment and one radial partition of still anotherlongitudinal compartment, and the order is repeated. Accordingly, it isdeemed that the exhaust gas is passed through a substantially coiledpath.

FIGS. 21 and 22 illustrates another exhaust pipe which is quite similarto that shown in FIGS. 19 and 20 except the quartered cross section ofthe exhaust pipe 130 substituted for the trisected cross section of thecorresponding pipe 120.

While particular embodiments of the invention have been illustrated anddescribed, modifications thereof will readily occur to those skilled inthe art. It should be understood therefore that the invention is notlimited to the particular arrangements and structures disclosed but thatthe appended claims are intended to cover all modifications which do notdepart from the true spirit and scope of the invention.

What we claim as new and desired to be secured by Letters Patent of theUnited States is:

1. In an exhaust gas muffler means, at least one buffing elementcomprising a blind buffing chamber having at least a throat and aplurality of outlets, exhaust gas being introduced into said buffingchamber through said throat and expelled out of said buffing chamberthrough said outlets, and said outlets being positioned so as to directsaid exhaust gas sidewise in connection with the direction of theincoming exhaust gas, the elastic coefiicient being adjusted so as toeffectively damp and absorb the energy of the pulsative dynamic pressureof the pressure waves and intermittent exhaust gas flow, by designing soas to satisfy the following formula:

wherein f represents the resonance oscillation frequency of the buffingchamber, g represents the acceleration of gravity or 980 crn./sec. Wrepresents the absolutepressure subjected to the buffing chamber fromthe throat by the pressure waves and the intermittent flow of theexhaust gas (in unit of kg./cm. and K represents the elastic coefficientof the buffing chamber, or KAkP,,S/H,, in which A is the proportionalconstant, k is the polytropic index, P is the pressure inside thebuffing chamber, S is the cross-sectional area of the throat, and H, isthe lateral length of the buffing chamber.

2. A buffing element as a component of said exhaust gas muffler means asclaimed in claim 1, comprising an outer casing, an inner chamber, and anexhaust gas incoming pipe,

said outer casing being jointed and communicated with a rear exhaustpipe,

said inner chamber being a blind buffing chamber communicated with saidexhaust gas incoming pipe through said throat only, and

said exhaust gas incoming pipe being provided with a plurality ofperforations, through which the same is communicated with the interiorof said outer casing.

3. A buffing element as a component of said exhaust gas muffler means asclaimed in claim 1, comprising an outer casing, an inner chamber, and anexhaust gas incoming pipe,

said outer casing being a part of said exhaust gas incoming pipe,

said inner chamber being a blind buffing chamber formed by a thin pipehaving a closed tail end and arranged concentrically to said exhaust gasincoming pipe, and

said thin pipe having a plurality of perforations at a part in theproximity of its opened head end forming said outlets and jointed withthe tail end of a frustoconical through pipe by which said exhaust gasincoming pipe is checked.

4. A buffing element as a component of said exhaust gas muffler means asclaimed in claim 1, comprising an outer casing, an inner chamber, and anexhaust gas incoming pipe,

said outer casing being a part of said exhaust gas incoming pipe,

said inner chamber being a blind buffing chamber formed by alongitudinally tubular space between said outer casing and a thin pipehaving an opened tail end jointed which said-exhaust-gas incoming pipeis-checked, and said thin pipe having a piuralityof perforations formingsaid 'outletsat a part in the proximity of its closed head end and beingarranged concentrically to said exhaust gas incoming pipe.

5. A buffing element as a component of said exhaust gas muffler means asclaimed in claim 1, comprising an outer casing, an inner chamber, and anexhaust gas incoming pipe, said outer casing being a part of saidexhaust gas incoming pipe, a I said inner chamber being a blindbuffing'chamber formed by an inside pipe arranged concentrically to.said exhaustgas incoming pipe and having a closed tail end,

and said inside pipe being circumferentially partly jointed with'andcircumferentially partly disengaged from the inside of said exhaust gasincoming pipe so as to form several longitudinally through troughsbetween said in- A side pipe and said exhaust gas incoming pipe. 6. Abuffing element as a component of said exhaust gas fmuffle r means asclaimed in claim 1, comprising anouter casing, an inner chamber, and anexhaust gas incoming pipe, a said outer casing being arrangedconcentrically to and.

around a part of said exhaust gas incoming pipe and having arcduced headend and a reduced tail end so as I to joint with said part, a a

. said pa'rtbeing divided into a front pipe and a rear pipe, said frontpipe having a plurality of perforations in x the proximity of its openedhead end and a closed 'tail end so as to form a blind bu'fflng chamber,and said rear pipe having an opened head end an opened tail end, so thatanother blind butting chamber is formed in the form of a tube betweensaid rear pipe and the rear part of said outer casing. 7. A buffingelement as a component of said exhaust gas muffler means as claimed inclaim 1, comprising an outer casing, an inner chamber, and an exhaustgas incoming pipe, said outer casing being a laterally expandedfrontward extension of a rear exhaust pipe having a closed head end,said lnncrchambcr being a blind buffing chamber formed by an cxpandbdpart having a closed tail end, of said exhsust gas incoming pipeextended into said outer casing, and said exhaust gas incoming pipehaving a plurality of perforations between said closed head end and saidexpanded part. 8. A buffing element as a component of said exhaust gasmuffler means as claimed in claim 1, comprising an outer csslng,-sninner chamber, and an exhaust gas incoming pipe,

said outer casing comprising a front chamber and a blind buffing chamberin which said exhaust gas incoming pipe extended through said frontchamber has an opened tail and,

said inner chsmbcr being said blind buffing chamber, and

said exhaust gas incoming pipe having a plurality of perforstlons in itspart arranged in said front chamber so as to communicate with a rearexhaust pipe which has an opened head end in said front chamber. 9. Abuffing element as a component of said exhaust gas muffler means asclaimed in claim 1, comprising an outer casing, an inner chamber, and anexhaust gas incoming plpc, said outer casing comprising a front chamber,ssldlnncr chamber being a blind buffing chamber comprising a blind talland of said exhaust gas incoming plpc extended through said frontchamber and out thereof, and

said exhaust gas incoming pipe having a plurality of .per-

forations in its part arranged in said front chamber so as 'tocommunicate with a rear exhaust pipe which has an opened head end insaid front chamber.

10. A buffing element as a component of said exhaust gas muffler meansas claimed in claim 1, comprising an outer casing, an inner chamber, andan exhaust gas incoming pipe,

said outer casing being a spheroidal chamber extended from a rear pipe,

said inner chamber being a blind buffing chamber arranged inside saidspheroidal chamber, and

said exhaust gas incoming pipe being extended into said inner chamberand provided with an opened tail end in said inner chamber andaplurality of perforations in said spheroidal chamber so as tocommunicate with a said rear pipe.

' 11. A group of buffing elements as components of said exhaust gasmuffler means as claimed in claim 1, comprising parts of said exhaustgas pipe itself, a

each of said parts being formed by dividing a length of said exhaust gaspipe into some longitudinal compartments by longitudinal partitions andthen dividing each of said longitudinal compartments into a series ofsubcompartments by lateral partitions extended only within saidrespective compartment, said lateral partition of any compartment beingzigzag arranged to another lateral partition ofany other compartment,and said longitudinal partition of any subcompartment being providedwith several perforations serving as said throat for said subcompartmentand as said outlets for an adjoining subcompartment and another severalperforations serving as said outlets for the first-named subcompartmentand as said throat for another adjoining subcompartment, whereby. saidex' haust gas is passed through said part along generally coiledpassage. 12. A group of buffing elements as claimed in claim 11, in

which said longitudinal compartments are two.

13. A group of buffing elements as claimed in claim 1 1,,in which saidlongitudinal compartments are three.

, 14. A group of buffing elements as claimed in claim. 11, in which saidlongitudinal compartments are four.

15. lnan exhaust gas muffler means, at least one buffing elementcomprising a blind buffing chamber having at least a throat and aplurality of outlets, exhaust gas being introduced into said buffingchamber through said throat and expelled out of said buffing chamberthrough saidoutletaand said outlets being positioned so as to directsaid exhaust gas sidewise in connection with the direction of theincoming exhaust gas, said buffing element including an outer casing, aninner chamber, an exhaust gas incoming pipe, and a semispherical gasguide,

, said outer casing being arranged concentrically to said exhaust gasincoming pipe and jointed with the rear end thereof intermediate areducer and a rear exhaust pipe intermediate another reducer,

said inner chamber being a blind buffing chamber formed between saidouter casing and a frontward extension of said rear exhaust pipe, and

said semispherical gas guide being arranged inside the firstnamedreducer in such a manner that an opened head end of said frontwardextension forming said outlets is partially covered thereby and thatsaid exhaust gas incoming pipe is communicated with said inner chamberoutside said gas guide andsaid inner chamber is communicated with saidopened head end inside gas guide.

16. A buffing element as a component of said exhaust gas muffler meansas claimed in claim 15, which is bent in whole in accordance with acurved longitudinal axis.

17. in an exhaust gas muffler means, at least one buffing elementcomprising a blind buffing chamber having at least a throat and aplurality of outlets, exhaust gas being introduced into said buffingchamber through said throat and expelled out of said buffing chamberthrough said outlets, and said outlets being positioned so as to directsaid exhaust gas sidewise in connection with the direction of theincoming exhaust gas, said buffing element comprising an outer casing,an inner chamber, an exhaust gas incoming pipe, and a semispheroidal gasguide,

said outer casing being arranged concentrically to saidex- I haust gasincoming pipe and having a head reduced part jointed with the rear endof said exhaust gas incoming pipe and a tail reduced part jointed with arear exhaust P p v said inner chamber being a blind buffing chamberformed between the rear half of said outer casing and an inner pipehaving an opened tail end and jointed with said tail reduced part, and

said semispheroidal gas guide having several axial ribs jointed withsaid outer casing in such a manner that an opened head end of said innerpipe forming said outlets in partially covered thereby and that saidexhaust gas incoming pipe is communicated with said inner chamberoutside said gas guide and said inner chamber is communicated with saidopened head end inside said gas guide.

1. In an exhaust gas muffler means, at least one buffing elementcomprising a blind buffing chamber having at least a throat and aplurality of outlets, exhaust gas being introduced into said buffingchamber through said throat and expelled out of said buffing chamberthrough said outlets, and said outlets being positioned so as to directsaid exhaust gas sidewise in connection with the direction of theincoming exhaust gas, the elastic coefficient being adjusted so as toeffectively damp and absorb the energy of the pulsative dynamic pressureof the pressure waves and intermittent exhaust gas flow, by designing soas to satisfy the following formula: f ( K X g/w) X (1/2) wherein frepresents the resonance oscillation frequency of the buffing chamber, grepresents the acceleration of gravity or 980 cm./sec.2, W representsthe absolute pressure subjected to the buffing chamber from the throAtby the pressure waves and the intermittent flow of the exhaust gas (inunit of kg./cm.2), and K represents the elastic coefficient of thebuffing chamber, or KAkPoS/Ho in which A is the proportional constant, kis the polytropic index, Po is the pressure inside the buffing chamber,S is the cross-sectional area of the throat, and Ho is the laterallength of the buffing chamber.
 2. A buffing element as a component ofsaid exhaust gas muffler means as claimed in claim 1, comprising anouter casing, an inner chamber, and an exhaust gas incoming pipe, saidouter casing being jointed and communicated with a rear exhaust pipe,said inner chamber being a blind buffing chamber communicated with saidexhaust gas incoming pipe through said throat only, and said exhaust gasincoming pipe being provided with a plurality of perforations, throughwhich the same is communicated with the interior of said outer casing.3. A buffing element as a component of said exhaust gas muffler means asclaimed in claim 1, comprising an outer casing, an inner chamber, and anexhaust gas incoming pipe, said outer casing being a part of saidexhaust gas incoming pipe, said inner chamber being a blind buffingchamber formed by a thin pipe having a closed tail end and arrangedconcentrically to said exhaust gas incoming pipe, and said thin pipehaving a plurality of perforations at a part in the proximity of itsopened head end forming said outlets and jointed with the tail end of afrustoconical through pipe by which said exhaust gas incoming pipe ischecked.
 4. A buffing element as a component of said exhaust gas mufflermeans as claimed in claim 1, comprising an outer casing, an innerchamber, and an exhaust gas incoming pipe, said outer casing being apart of said exhaust gas incoming pipe, said inner chamber being a blindbuffing chamber formed by a longitudinally tubular space between saidouter casing and a thin pipe having an opened tail end jointed with thehead end of a frustoconical through pipe, by which said exhaust gasincoming pipe is checked, and said thin pipe having a plurality ofperforations forming said outlets at a part in the proximity of itsclosed head end and being arranged concentrically to said exhaust gasincoming pipe.
 5. A buffing element as a component of said exhaust gasmuffler means as claimed in claim 1, comprising an outer casing, aninner chamber, and an exhaust gas incoming pipe, said outer casing beinga part of said exhaust gas incoming pipe, said inner chamber being ablind buffing chamber formed by an inside pipe arranged concentricallyto said exhaust gas incoming pipe and having a closed tail end, and saidinside pipe being circumferentially partly jointed with andcircumferentially partly disengaged from the inside of said exhaust gasincoming pipe so as to form several longitudinally through troughsbetween said inside pipe and said exhaust gas incoming pipe.
 6. Abuffing element as a component of said exhaust gas muffler means asclaimed in claim 1, comprising an outer casing, an inner chamber, and anexhaust gas incoming pipe, said outer casing being arrangedconcentrically to and around a part of said exhaust gas incoming pipeand having a reduced head end and a reduced tail end so as to joint withsaid part, said part being divided into a front pipe and a rear pipe,said front pipe having a plurality of perforations in the proximity ofits opened head end and a closed tail end so as to form a blind buffingchamber, and said rear pipe having an opened head end an opened tailend, so that another blind buffing chamber is formed in the form of atube between said rear pipe and the rear part of said outer casing.
 7. Abuffing element as a component of said exhaust gas muffler means asclaimed in claim 1, comprising an outer casing, an innEr chamber, and anexhaust gas incoming pipe, said outer casing being a laterally expandedfrontward extension of a rear exhaust pipe having a closed head end,said inner chamber being a blind buffing chamber formed by an expandedpart having a closed tail end, of said exhaust gas incoming pipeextended into said outer casing, and said exhaust gas incoming pipehaving a plurality of perforations between said closed head end and saidexpanded part.
 8. A buffing element as a component of said exhaust gasmuffler means as claimed in claim 1, comprising an outer casing, aninner chamber, and an exhaust gas incoming pipe, said outer casingcomprising a front chamber and a blind buffing chamber in which saidexhaust gas incoming pipe extended through said front chamber has anopened tail end, said inner chamber being said blind buffing chamber,and said exhaust gas incoming pipe having a plurality of perforations inits part arranged in said front chamber so as to communicate with a rearexhaust pipe which has an opened head end in said front chamber.
 9. Abuffing element as a component of said exhaust gas muffler means asclaimed in claim 1, comprising an outer casing, an inner chamber, and anexhaust gas incoming pipe, said outer casing comprising a front chamber,said inner chamber being a blind buffing chamber comprising a blind tailend of said exhaust gas incoming pipe extended through said frontchamber and out thereof, and said exhaust gas incoming pipe having aplurality of perforations in its part arranged in said front chamber soas to communicate with a rear exhaust pipe which has an opened head endin said front chamber.
 10. A buffing element as a component of saidexhaust gas muffler means as claimed in claim 1, comprising an outercasing, an inner chamber, and an exhaust gas incoming pipe, said outercasing being a spheroidal chamber extended from a rear pipe, said innerchamber being a blind buffing chamber arranged inside said spheroidalchamber, and said exhaust gas incoming pipe being extended into saidinner chamber and provided with an opened tail end in said inner chamberand a plurality of perforations in said spheroidal chamber so as tocommunicate with said rear pipe.
 11. A group of buffing elements ascomponents of said exhaust gas muffler means as claimed in claim 1,comprising parts of said exhaust gas pipe itself, each of said partsbeing formed by dividing a length of said exhaust gas pipe into somelongitudinal compartments by longitudinal partitions and then dividingeach of said longitudinal compartments into a series of subcompartmentsby lateral partitions extended only within said respective compartment,said lateral partition of any compartment being zigzag arranged toanother lateral partition of any other compartment, and saidlongitudinal partition of any subcompartment being provided with severalperforations serving as said throat for said subcompartment and as saidoutlets for an adjoining subcompartment and another several perforationsserving as said outlets for the first-named subcompartment and as saidthroat for another adjoining subcompartment, whereby said exhaust gas ispassed through said part along a generally coiled passage.
 12. A groupof buffing elements as claimed in claim 11, in which said longitudinalcompartments are two.
 13. A group of buffing elements as claimed inclaim 11, in which said longitudinal compartments are three.
 14. A groupof buffing elements as claimed in claim 11, in which said longitudinalcompartments are four.
 15. In an exhaust gas muffler means, at least onebuffing element comprising a blind buffing chamber having at least athroat and a plurality of outlets, exhaust gas being introduced intosaid buffing chamber through said throat and expelled out of saidbuffing chamber through said outlets, and said outlets being positionedso as to direct said exhaust gas sidewise in connection with thedirection of the incoming exhaust gas, said buffing element including anouter casing, an inner chamber, an exhaust gas incoming pipe, and asemispherical gas guide, said outer casing being arranged concentricallyto said exhaust gas incoming pipe and jointed with the rear end thereofintermediate a reducer and a rear exhaust pipe intermediate anotherreducer, said inner chamber being a blind buffing chamber formed betweensaid outer casing and a frontward extension of said rear exhaust pipe,and said semispherical gas guide being arranged inside the first-namedreducer in such a manner that an opened head end of said frontwardextension forming said outlets is partially covered thereby and thatsaid exhaust gas incoming pipe is communicated with said inner chamberoutside said gas guide and said inner chamber is communicated with saidopened head end inside gas guide.
 16. A buffing element as a componentof said exhaust gas muffler means as claimed in claim 15, which is bentin whole in accordance with a curved longitudinal axis.
 17. In anexhaust gas muffler means, at least one buffing element comprising ablind buffing chamber having at least a throat and a plurality ofoutlets, exhaust gas being introduced into said buffing chamber throughsaid throat and expelled out of said buffing chamber through saidoutlets, and said outlets being positioned so as to direct said exhaustgas sidewise in connection with the direction of the incoming exhaustgas, said buffing element comprising an outer casing, an inner chamber,an exhaust gas incoming pipe, and a semispheroidal gas guide, said outercasing being arranged concentrically to said exhaust gas incoming pipeand having a head reduced part jointed with the rear end of said exhaustgas incoming pipe and a tail reduced part jointed with a rear exhaustpipe, said inner chamber being a blind buffing chamber formed betweenthe rear half of said outer casing and an inner pipe having an openedtail end and jointed with said tail reduced part, and saidsemispheroidal gas guide having several axial ribs jointed with saidouter casing in such a manner that an opened head end of said inner pipeforming said outlets in partially covered thereby and that said exhaustgas incoming pipe is communicated with said inner chamber outside saidgas guide and said inner chamber is communicated with said opened headend inside said gas guide.